GENTECH archive 8.96-97

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Re:Death and Transfiguration of FOEE Mailout



Jon Buckingham wrote:
> 
> Hi,
> 
> I have a specific question from the following text, which appears to
> contradict another posting -
> 
> >  FRIENDS OF THE EARTH EUROPE                                   						BIOTECHNOLOGY
> >  PROGRAMME
> >
> >   Mailout Vol. 3 (1997), Issue 1, 31st January 1997
> >
> > <snip>
> >
> >  Concerns about the antibiotic :
> >
> >  There is no evidence that genes from plants have been ever transferred
> >  under natural conditions to bacteria.
> 
> And from another previous posting by "andy" at South Downs EF!
> (<savage@easynet.co.uk>) ...
> 
> > TRANSFER OF FOREIGN GENE TO MICRO-ORGANISM
> > It was reported in 1994 that gene transfer can occur from plants to
> > micro-organisms. Genetically engineered oilseed rape, black mustard,
> > thorn-apple and sweet peas all containing an antibiotic-resistance gene
> > were grown together with the fungus Aspergillus niger or their leaves
> > were added to the soil. The fungus was shown to have incorporated the
> > antibiotic-resistance gene in all co-culture experiments (Hoffmann T,
> > Golz C & Schieder O (1994) Foreign DNA sequences are received by a
> > wild-type strain of Aspergillus niger after co-culture with transgenic
> > higher plants. Curr. Genet. 27: 70-76.). It is worth noting that micro-
> > organisms can transfer genes through several mechanisms to other
> > unrelated micro-organisms.
> 
> I release gene transfer did not occur to *bacteria*, but since
> transfer did occur to different micro-organisms, it doesn't seem a
> huge leap of faith for a layman like myself to assume it *may* be
> possible to directly or indirectly spread to bacteria.
> 
> Any comments?
This may help (or make things worse!) I suppose a definition of natural
conditions in this context would help. 
Andy

Just a thought:
FOEE mailout
 "The PAT gene is only used as a marker gene."

How do the organisms know this, and would they care even if they did?
Do they know how to play cricket?
---------------------------------------------------------------

Gene Tinkering Blues Vol.2 Issue 4 February 1997

  "Death and Transfiguration"

Text Only

Genetically engineered crop plants contain genes for antibiotic
resistance. Such genes are used early in the selection of genetically
engineered cells to be regenerated into mature crop plants. Though used
in a fleeting manner very briefly early in the engineering process, the
antibiotic tolerance genes are present as 'marker' genes in each cell of
the crop. Such genes can be transferred to pathogenic bacteria in the
guts of animals feeding on the crops or in the soil. Bacteria enjoy a
form of sex after death that has been called 'death and
transfiguration.' In death and transfiguration living bacteria scavenge
genes from dead ones. Bacteria also spread genes by mating and some
bacteria can mate with widely different species of bacteria. The
noteworthy concern about antibiotic tolerance is that by flooding the
environment with antibiotic tolerance genes the usefulness of
antibiotics will disappear. Antibiotic tolerance genes frequently have
the ability to act on classes of antibiotics so that restricting some
antibiotics to medical application is not necessarily an effective
strategy. By overuse of antibiotics and spread of resistance genes,
diseases such as tuberculosis and cholera have begun to produce
epidemics of disease that have no effective treatment other than
expensive isolation and quarantine procedures.

Clearly resistance genes can be transferred from bacteria that do not
cause disease to those that cause epidemics in the digestive system of
animals. Resistance genes have been transferred from resistant to
sensitive bacteria on the surface of towels used to clean the teats of
cattle with mastitis, on the surface of meat cutting boards and in the
feces of pigs. Resistance genes in crop plants are bound to be
transferred from the crops to sensitive bacteria in the gut, feces or
soil. Nevertheless, 'experts' from the biotechnology industry argue that
such transfers are not significant.

There is a technical problem that renders the direct detection of
resistance genes in transfers between antibiotic sensitive and resistant
bacteria technically challenging. Many of the bacteria that do not cause
disease are tough soil bacteria that have thick protective envelopes
that prevent penetration of antibiotics. When samples from soil, feces
or digestive system are analyzed numerous colonies grow on antibiotic
containing media but these colonies are from nonpathogenic bacteria with
thick selective walls not the tolerance genes that make pathogens
resistant to antibiotics. Here-to-fore, experiments have not been done
that would detect transfer of resistance genes from crops to pathogenic
bacteria. However, such experiments are possible using a technique
called polymerase chain reaction (PCR) in genetic fingerprinting.

Many pathogenic bacteria mate with other bacteria but do not take up
genes from the media (transformation) unless environmental conditions
are manipulated such as by adding calcium ions and natural chemicals
that alter bacterial permeability. Other bacteria take up genes during
growth periods called competence. Some bacteria are called 'promiscuous'
because they can mate with virtually any bacterium and transfer
antibiotic resistance during mating. In the ecosystem of the gut those
bacteria that easily pickup and transfer resistance genes are mixed with
pathogens who must submit to the promiscuous mater.

Antibiotic resistant disease bacteria are beginning to overwhelm the
public health control that was achieved nearly sixty years ago after
antibiotics were discovered. Antibiotic control is disappearing because
antibiotics are over used. Antibiotics are used extensively in animal
production to enhance weight gain, in fish farming to prevent disease
spread and in human disease treatment. The human diseases with growing
demand for antibiotics are those that compromise the immune system.
These diseases include HIV, cancer treatment, organ transplant and
treatment of autoimmune disease such as Lupus or arthritis. Putting
antibiotic tolerance genes into crops will accelerate the growing loss
in usefulness of antibiotics that will cause growing epidemics of
disease.

Genetically engineered microbes (GEMS) have not yet been extensively
released to the environment but it is well established that GEMS are
carried out of research laboratories on the laboratory coats of
investigators .Even though such releases release hundreds of billions of
microbes on each coat such releases are minute when compared with the
microbes populating a release to soil or as a dietary supplement. GEMS
being prepared for release include microbes added to soil to enhance
crop yield, microbes for frost protection, microbes for remediating
polluted soil and various GEMS for food supplements and beverages
including beer. GEMS should not be released to the environment if they
contain genes for antibiotic tolerance. As a general principle that
genetic engineering design should be directed towards minimizing
intrinsic traits of microbes that allow them to transfer genetic
information to other microorganisms. However, that principle may
conflict fundamentally with the genetic basis of the organism
themselves.

References:

6 Special Issues 'Death and transfiguration among bacteria' N.Higgins
TIBS17,207,1992 'Clean white coats spread mutant microbes 'New Scientist
21 March 1992 'R-Plasmid transfer in a patient with a mixed infection'
Epedemiol.Infect.112,247,1994 'Transfer of Multiple Drug Resistance
Plasmids' Applied and Environmental Microbiology 60,4015,1994. 'Natural
Genetic Transformation in the Environment' Microbial Reviews 58,563,1994

Prof. Joe Cummins Professor Emeritus Genetics University of Western
Ontario 738 Wilkins Street London, Ontario N6C4Z9 Canada phone&FAX 519
681 5477 e-mail jcummins@julian.uwo.ca 
-----------------------
Rational debate isn't working, how can we stop them?
If a load of crusties blockade their offices they just get dismissed as
ill informed scare mongers. How about a thousand well informed, well
dressed, normal people the mass of the population can relate to actually
saying "we've had enough. You have got to stop now!" Something that
couldn't just be dismissed as 'protesters'
Anyone want to discuss the possibility? (please, before I 'dissappear')
Andy


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